Weighing and height measuring device

ABSTRACT

A device for measuring weight and/or height especially adapted for use with a remote digital read-out system comprising a mechanical leverage weighing structure having a high degree of sensitivity and low friction and hysteresis coupled with a compatible electronic measuring system and/or a height measuring means compatible with said system.

United States Patent Hutchinson et al.

[ 1 June 6,1972

[54] WEIGHING HEIGHT MEASURING DEVICE [72] Inventors: William Y.Hutchinson, Chicago; Walter P. Kushmult, Niles, both of 111.

Continental Scale Corporation, Chicago, 111.

[22] Filed: Oct. 26, 1970 [21] Appl. No.: 83,924

[73] Assignee:

[52] 11.8. C1. ..177/245, 177/50, 177/210, I 73/432 R, 33/169 R [51]Int. Cl. ..G0lg 23/37, 601g 19/50 [58] Field oisearch..i77/l,50,210,211,245; 73/432 R; 33/169 R [56] References Cited UNITEDSTATES PATENTS 2,836,980 6/1958 Giepen ..33/l72 E X 3,027,761 4/1962Lauro 177/245 X 3,221,543 12/1965 Hall etal .;.l77/2i0 X FOREIGN PATENTSOR APPLICATIONS 521,101 5/1940 Great Britain ..|77/24s 153,572 11/1963U.S.S.R ..'.....33/169R OTHER PUBLlCATlONS Metalworking Production,periodical, issue for March 25, 1964, pages 67 and 68.

Primary Examiner-Robert S. Ward, Jr.

Attorney-Johnston, Root, OKeefie, Keil, Thompson 8!. Shurtleff [57]ABSTRACT A device for measuring weight and/or height especially adaptedfor use with a remote digital read-out system comprising a mechanicalleverage weighing structure having a high degree of sensitivity and lowfriction and hysteresis coupled with a compatible electronic measuringsystem and/or a height measuring means compatible with said system.

6 Claims, 2 Drawing Figures WEIGI'IING AND HEIGHT MEASURING DEVICEBACKGROUND OF THE INVENTION Many different weighing devices and heightmeasuring devices have heretofore been proposed. The usual type ofweighing scale consists of aweighing platform and a series of levers ora spring arranged so that the person being weighed can view a scaleshowing his weight. Height measurement is usually obtained by manuallyadjusting the height measuring rod. Most of these devices are relativelysimple. Others are fairly complex depending upon the accuracy requiredand the conditions.

In recent years various types of weighing systems have been proposedwhich involve the use of differential transformers.

Examples of such systems are those disclosed in U.S. Pat. Nos. 1

OBJECTS One of the objects of this invention is to provide a new andimproved device for measuring weight and/or height adapted for useeither integrally or with a remote digital read-out system and/or acomputer input signal comprising a mechanical leverage weighing systemhaving a high degree of sensitivity and low friction and hysteresiscoupled with a compatible electronic measuring system and/or a heightmeasuring means compatible with said system.

. Another object of the invention is to provide a new and improvedcompact weight and height measuring apparatus which is especiallyadapted for use in hospitals and medical centers and for use with othertypes of examination equipment normally employed in hospitals andmedical centers.

Other objects and advantages of the invention will appear from thefollowing description in conjunction with the. accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, FIG. 1 is aperspective view illustrating one embodiment of the invention; and

FIG. 2 is an elevational sectional view taken along lead line 2--2 ofFIG. 1.

BRIEF SUMMARY OF THE INVENTION A In accordance with the invention aweight and height measuring apparatus is provided comprising incombination a base, a weight responsive movable platform mounted on saidbase, a hollow pillar mounted on said base and having openings in thesides thereof, a first housing on one side of said pillar providing anenclosed space communicating with one of said openings in said pillar, asecond housing on another side of said pillar providing an enclosedspace communicating with another of said openings in said pillar,weighting mechanism in said first housing connected through one saidopening in said pillar to said platform, and height measuring means insaid pillar and said second housing and extending through another saidopening in said pillar.

The apparatus is further characterized by the fact that said firsthousing encloses a variable inductance transducer which generates asignal in response to weight on said platform and said second housingencloses a variable resistance transducer which generates a signal inresponse to height as measured by said height measuring means.

The mechanical structure of the weighting apparatus is also an importantfeature of the invention in that it provides a high degree ofsensitivity together with low friction and hysteresis and is compatiblewith an electronic measuring system.

DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. 1 of thedrawings, the apparatus illustrated comprises a base generally indicatedat 1, av weight responsive moving platform generally indicated at 2, ahollow pillar 3 which is mounted and affixed to said base, a firsthousing 4 on one side of said pillar providing an enclosed space, asecond housing 5 on the opposite side of said pillar providing anenclosed space, a height measuring rod generally indicated at 6 which isprovided with a projecting portion 7 adapted to be placed on the head ofthe person whose height is being measured, and a digital read-out unitgenerally indicated at 8 where both weight measurements and heightmeasurements can be read directly in terms of pounds or kilograms andinches or centimeters. The read-out unit 8 is connected to the outputconnector in the base 1 by a cable generally indicated at 9 whichincludes connections 10 from the unit in housing 5 as well as those fromthe unit inhousing 4.

In FIG. 2 the base 1 consists of an inner base 11 and an outer base 12.The outer base 12 is connected to the inner base 11 by means of brackets13,13, 14,14, and machine screws 15,15. The brackets 13,13 are securedto the inner wall of the outer base 12 by welding or in any othersuitable manner, the brackets 14,14 are secured to the outer wall of theinner base 11 by welding or in any other suitable manner, and thebrackets 13,13 and 14,14 are screwed together by machine screws 15,15which also connected to the feet 16,16. The latter are adapted to reston the floor or other surface and to assist in preventing tilting of theapparatus.

The housings 4 and 5 rest on the upper surfaces of the outer base atpoints 17 and 18 and are secured to the outer walls of the pillar 3 bymeans of bolts 19,20,21 and 22 which are adapted to receive keyholeopenings on the inner sides of the housings 4 and 5 so that the housings4 and 5 can be removed by lifting them upwardly and pulling outwardly.

The weighing system comprises a beam 23'extending in a generallyhorizontal direction through an opening24 in the pillar 3. Beam 23 issupported adjacent the pillar 3 from a knife edge pivot 25 in contactwith a V-bearing 26 which is affixed to a beam loop 27 disposed over apillar hook 28. An arm 29 of the pillar hook 28 is threaded at one endand fastened to pillar 3 by nuts 30,31.

The end 32 of beam 23 is connected by knife edge pivot 33, V-bearing 34and beam loop 35 to steel yard hook 36 which in turn is connected to theplatform and its associated mechanism so that hook 36 moves in responseto and acts as a transmission means for any weight imparted to theplatform 2 and its associated mechanism. The platform 2 and its'associated mechanism are conventional. Hence, no detailed descriptionis necessary. For the sake of clarity the platform 2 is not shown inFIG. 2 but if shown it would occupy a position approximatelycorresponding to a line through the top side of the outer base.

The outer end 37 of beam 23 is connected through knife edge pivot 38,V-bearing 39 and beam loop 40 to the Upper end of main spring 41 which,as shown, is a coil spring. The lower end of main spring 41 is securedto plate 42 by an adjusting rod 43 which is threaded to receiverotatable knob 44. The upper end 45 of adjusting rod 43 is flanged andaffixed to a member 46 disposed between the lower coils of spring 41.This arrangement constitutes a means for adjusting the weighingmechanism to a zero position. By turning knob 44 the members 43 and 46move axially. When the member 46 is rotated clockwise the length ofspring 41 is increased, thereby increasing the tension. When member 40is rotated in the opposite direction the length of spring'41 isdecreased thereby reducing the tension. Initial calibration of themechanical system can be achieved by rotating the adjusting rod 43 whichrotates member 46 in the coils of spring 41, thereby changing the numberof effective coils which changes the spring rate accordingly.

At a point intermediate between pivot 25 and pivot 38 knife edge pivot47, V-bearing 48 and beam loop 49 connect beam 23 to beaded chain 50which serves as a floating connection to plunger sleeve 51, the latterbeing connected to beaded chain 50 by means of set screw 52. Plungersleeve 51 is threaded at one end and secured to plunger rod 53 which isalso threaded in order to provide the connection. Plunger rod 53 at itslower end is the core of linear variable differential transformer 54.Transformer 54 is held in place by holder 55 which is connected to base11. The voltage output of transformer 54 is transmitted by means ofwires 9 to the read-out unit 8 shown in FIG. 1.

The measuring rod assembly consists of two telescoping members 56 and 57disposed within pillar 3 in the front portion thereof. One of these isnormally fastened to the base 11 and the other one is movable verticallyto any height corresponding to the height of the person to be measured.The ultimate height usually does not exceed 8 feet. It will beunderstood that member 7 is pivoted at 58 so that it can be moved from avertical to a horizontal position or vice versa. A pulley 59 is mountedfor rotation on a stud 60, the latter being. affixed to the front sideof pillar 3. A wire 61 which is usually or 6 feet in length and whichnormally serves as a winding in the height transducer 62 passes aroundpulley 59 and is fastened adjacent one end of the rod 56 so that whenthe rod 56 is raised or lowered the wire 61 will be correspondinglymoved out or into height transducer 62.

Height transducer 62 in the embodiment shown is a variable resistancetransducer, viz., a multitum potentiometer, which is connected by meansof wires (FIG. 1) to the digital readout unit 8. Height transducer 62 isfastened to bracket 63 by machine screws 64,65 or in any other suitablemanner and bracket 63 is welded or otherwise fastened to the top member42 of inner base assembly 11.

Pillar 3 is also fastened by means of bolts 66 and 67 and brackets 68and 69 to the top member 42 of base 11. The brackets 68 and 69 arewelded or otherwise secured to pillar 3.

MODE OF OPERATION When an object or person to be weighed is placed onthe platform 2 the steel yard hook 36 is drawn downwardly causing thebeam 23 to be pulled downwardly at end 32 on pivot 33 and aroundsupporting pivot 25 and its associated V-bearing 26. This causes rod 53to be raised. Since rod 53 serves as a core of differential transformer54 raising the rod 53 will alter the output of said transformer apredetermined amount depending upon the distance the rod is raised. Inthe embodiment shown, pivots 33 and 47 are equally spaced from pivot 25and the ratio of the distance to pivot 38 is such that when pivot 38passes through a vertical distance of 2 inches pivots 47 and 33 willpass through a vertical distance of 0.5 inch. Because of thisarrangement, it is possible to practice the invention so as to provide aworking range with or without passing through the null point of thetransformer.

The apparatus is sensitive to a weight of 10 grams. The leverage ratioin the platform is 10:1. The beam ratio is 421. When the apparatus isused for weighing persons the maximum weight limit is usually taken tobe 400 pounds. The linear variable differential transformer 54 can be astandard piece of equipment, for example, a differential transformerwith a 6 volt DC input and a 1.8 volt DC output. Where it is desired touse the apparatus on an alternating current circuit the usual rectifiersand voltage reducers can be employed. It will be apparent that under thearrangement described 0.005 inch movement of rod 53 corresponds to adifferential of 1 pound in weight. Since the output of the transformer54 is 1.8 volts each pound on the weight scale corresponds to 0.04 of1.8. By transmitting the output voltage to the digital read-out unit 8the weight measurement can be read on a numerical basis by using aconventional digital unit. In the present case this unit is modified ina conventional manner to read either pounds or kilograms simply bypressing a pushbutton on the front of the unit.

It will be recognized that other types of variable inductancetransducers as well as variable resistance transducers can be usedinstead of a linear variable differential transformer. Also othermodifications can be made in the read-out unit, for example, theread-out unit can be made so that nothing shows in the window thereofuntil a button is pushed. The read-out can also hold the last reading.Likewise it can have an electronic zero control. It will be understood,of course, that the invention is not limited to units of any particularvoltage.

The height measuring unit also makes it possible to use a conventionaltype digital voltmeter in the read-out unit and the read-out unit ispreferably adjusted so that the height can be read either in inches orcentimeters.

An apparatus of the type described has a number of advantages. Thedeflection of the beam 23 is relatively large, the stresses on thespring wire 41 are relatively low. Usually only 20 percent of thecapability of the spring is employed. This reduces the friction on theknife head and also makes it possible to work well below the yield pointof the spring. Since the spring is relatively long there is moresensitivity on the pivots. The mechanical zero adjustment of the springchanges the number of active coils and the floating suspension 50permits accurate movement of rod 53. At the same time the apparatus isquite compact. The opening 70 through which wire 61 passes is adjacentthe front of pillar 3 so that the height measuring device does notinterfere with the weight measuring mechanism which is positioned towardthe rear of pillar 3.

With respect to the height measuring device, it will be understood thatother types of variable resistance units can be employed. It will alsobeunderstood that the number of turns of wire within the unit can bevaried and that the read-out unit can be adjusted in accordance with therequirements of the particular resistance unit.

It will be recognized that the invention makes it possible to adjust thetension on spring 41 as well as the rate of the spring, i.e., the valueper unit deflection.

While the structure shown embodies two separate housings, they can becombined in a single housing. In either case a multiplicity ofparameters, e.g., weight in pounds and/or kilograms and height in inchesand/or centimeters can be read on a single digital read-out unit.

The invention is hereby claimed as follows:

1. A weight and height measuring apparatus comprising in combination abase, a weight responsive movable platform mounted on said base, ahollow pillar mounted on said base and having openings in the sidesthereof, a first housing on one side of said pillar providing anenclosed space communicating with one of said openings in said pillar, asecond housing on another side of said pillar providing an enclosedspace communicating with another of said openings in said pillar,weighing mechanism in said first housing connected through one saidopening in said pillar to said platform, and height measuring means insaid pillar and said second housing and extending through another saidopening in said pillar.

2. An apparatus as claimed in claim 1 in which said first housingencloses a variable inductance transducer which generates a signal inresponse to weight on said platform.

3. An apparatus as claimed in claim 1 in which said second housingencloses a variable resistance transducer which generates a signal inresponse to height as measured by said height measuring means.

4. An apparatus as claimed in claim 1 in which said first housingencloses a linear variable differential transformer which generates asignal in response to weight on said platform and said second housingencloses a variable resistance transducer which generates a signal inresponse to height as measured by said height measuring means, theoutput of said transformer and the output of said voltmeter beingconnected to a common remote digital read-out means operable to deliverweight readings in pounds and kilograms and height readings in inchesand centimeters.

5. In a weight and height measuring apparatus, the combination ofweighing means including a variable inductance transducer and heightmeasuring means including a variable resistance transducer, and a singledigital read-out unit connected to the outputs of said transducerswhereby weight and height can both be read on said read-out unit.

6. An apparatus as claimed in claim 5 in which said read-out v 5 unit isremote.

l i k 2 533 v UNllED STATES PATENT OFFICE CERTIFICATE ()F CORRECTEGN mmNo. 5 7 5 Dated J 6, 1972 Inventor(s) William Y. Hutchinson and WalterP. Kushmuk It is certified that error appears in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:

Column '1, line 61, "Weighting" should read weighing Column 4, line 70,olaimk, "voltmeter" should read transducer Signed and sealed this 24thday of October 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Commissioner of PatentsAttesting Officer Patent No.

. UNITED STATES- PATENT OFFICE CERTIFICATE OF CORRECTION Dated June 6.1972 Invencofls) William Y. Hutchinson and" Walter P. Kushmuk It iscertified that: error appears in the above-identified patent:

and that said Letters Patent are hereby corrected as shown below:

Column 5, line 66, "0.04" should read Column 4, line 25, tension Signedand (SEAL) A test:

II. FLETCHER, AttestingOfficer "'0.005" should"read 0.00125 line 69,

0.0025 1 "number of active" coils' should read sealed this 1st day ofMay 1973.

JR. ROBERT GOTTSCHALK Commissioner of Patents

1. A weight and height measuring apparatus comprising in combination abase, a weight responsive movable platform mounted on said base, ahollow pillar mounted on said base and haviNg openings in the sidesthereof, a first housing on one side of said pillar providing anenclosed space communicating with one of said openings in said pillar, asecond housing on another side of said pillar providing an enclosedspace communicating with another of said openings in said pillar,weighing mechanism in said first housing connected through one saidopening in said pillar to said platform, and height measuring means insaid pillar and said second housing and extending through another saidopening in said pillar.
 2. An apparatus as claimed in claim 1 in whichsaid first housing encloses a variable inductance transducer whichgenerates a signal in response to weight on said platform.
 3. Anapparatus as claimed in claim 1 in which said second housing encloses avariable resistance transducer which generates a signal in response toheight as measured by said height measuring means.
 4. An apparatus asclaimed in claim 1 in which said first housing encloses a linearvariable differential transformer which generates a signal in responseto weight on said platform and said second housing encloses a variableresistance transducer which generates a signal in response to height asmeasured by said height measuring means, the output of said transformerand the output of said voltmeter being connected to a common remotedigital read-out means operable to deliver weight readings in pounds andkilograms and height readings in inches and centimeters.
 5. In a weightand height measuring apparatus, the combination of weighing meansincluding a variable inductance transducer and height measuring meansincluding a variable resistance transducer, and a single digitalread-out unit connected to the outputs of said transducers wherebyweight and height can both be read on said read-out unit.
 6. Anapparatus as claimed in claim 5 in which said read-out unit is remote.